Dilfer spilled the beans on the Seahawks' offense. Defensive-minded head coach Mike Nolan took copious notes. And the 49ers, who went 7-9 and allowed the most points in the NFL, resembled the Steel Curtain Steelers when they played Seattle, which finished 9-7 and won the NFC West.

Week 11: 49ers 20, Seahawks 14. Week 15: 49ers 24, Seahawks 14.

"We beat Seattle those two times my first year with the Niners because I gave them the entire offensive playbook," Dilfer said. "I was calling out the plays before they happened. Holmgren hasn't forgiven me to this day. And Hasselbeck was so mad at me because we were best friends. But I was devoted to the 49ers and winning the game."

Seven years later, the pieces are in place for a similar story line to unfold when the 49ers open the regular season Sunday against the Packers at Candlestick Park.

Last week, the Packers signed Scott Tolzien to the practice squad after Tolzien spent the past two seasons with head coach Jim Harbaugh and offensive coordinator Greg Roman as San Francisco's third-string quarterback.

At the University of Wisconsin, Tolzien was a two-time academic All-Big Ten selection who had a 3.6 GPA and interned at Merrill Lynch. His brains help explain why he's in the NFL despite possessing below-average arm strength and speed. His beautiful mind also makes him an ideal informant.

Dilfer isn't convinced Tolzien will be a key to the game, but he doesn't dismiss the possibility.

"I think if you're the Green Bay Packers and you want to be taken behind the veil, so to speak, of what the 49ers do, the best guy to get is Scott Tolzien," said Dilfer, now an ESPN analyst. "Because the whole reason he was on the 49ers' roster is because he was a smart guy. It wasn't because he was a highly talented player.

"There's tremendous advantage, especially when you play the 49ers, because so much of their success has come because of Greg Roman's new wrinkles that he's given to offensive football, the deception that he's implemented into this offense."

Dilfer said such information gathering is routine in the NFL, but the quality of intel is often determined by the players providing it. In 2006, he was a 12-year veteran with 123 career starts who had spent four years in Seattle, making him an excellent disseminator of information.

On Monday, the Packers signed another ex-49ers quarterback, Seneca Wallace, but he's unlikely to provide much insight after spending fewer than two weeks with San Francisco this summer. Instead, Green Bay's staff probably will pepper Tolzien with questions.

"The right questions are, 'Why do they do that?' " Dilfer said. " 'Why do they use this formation? What tendencies do they have in this personnel grouping? What are they looking at on defense when they come to the line of scrimmage with multiple plays?

" 'What are their protection checks? When you come up on a blitz and show something, what are they scared of? What will they check out of and into in those situations?' "

The Packers presumably will have no shortage of questions based on their defensive performance last season against the 49ers. In two losses, one in the divisional playoffs, Green Bay allowed an average of 37.5 points and 478 total yards while San Francisco's starting quarterbacks - Alex Smith and Colin Kaepernick - accounted for six touchdowns and posted a 106.9 passer rating.

Now, how much can the third-string quarterback on that 49ers team help them? It should be noted that Tolzien didn't have access to San Francisco's game plan: He was released Aug. 27, before the players were presented with their Week 1 marching orders.

Still, it's possible he could play a role in Sunday's game, without taking a snap. Such a thing has happened before.

"We weren't very good," Dilfer said of the 2006 49ers, "but we felt like the Seahawks couldn't move the ball because of the information we had."